The present invention relates to a soundproof wall. It aims at limiting the effects of the noise, among other things noises issued from various modes of transportation (roads, railways, airports). This soundproof device may be arranged on any type of infrastructure (wall, ceiling, floor, tunnel, building, . . . ).
The solution consisting in covering certain portions of roads or of motorways is not always possible. Often, it is sought to attenuate, if not to suppress, the effects of the noise by the construction on the bank of the carriageway, soundproof walls, also called acoustic screens, along the existing carriageways.
The conception of these soundproof walls results from the application of the circular R/A 89.66 dated 17 May 1989 which defines the requirements thereof in terms of noise, aesthetics and cost.
Generally, it is known that the sizing method of such walls is based on the calculation of the direct transmissions and on the calculation of sound attenuation by absorption, by reflection and by diffraction.
The absorbing panels are generally in the form of a caisson wherein is placed an absorbing material such as mineral wool, clay foam, etc. . . . whereas the masking panels are made of a hard wall such as glass, smoothed concrete, etc . . . .
The present invention falls into the former category, i.e the field of sound-absorbing panels. The device offered forms not only a sound-proof shield, but also enables the absorption thereof and reduces the effect of multiple reflections.
The purpose of the invention is to improve the performances of a soundproof wall fitted with absorbing panels while offering a new geometry consisting, among other things, in increasing the interaction surface of the acoustic waves with a partially absorbing material.
The invention falls within the framework of so-called fractal geometries and space filling surfaces. In particular, it has been sought here to realise such an object in a practical manner, which imposes a restriction on the first orders of fractality.